Start to implement requests limit

src/constants.rs

@@ -57,6 +57,9 @@ pub mod database_tables_names {
     pub const NOTIFICATIONS_TABLE: &str = "comunic_notifications";
 }
 
+/// Lifetime of limit counter (1 hour)
+pub const LIMIT_COUNTER_LIFETIME: u64 = 60 * 60;
+
 /// The account image to show for user who do not have any
 pub const DEFAULT_ACCOUNT_IMAGE: &str = "avatars/0Reverse.png";